U.S. patent number 7,228,179 [Application Number 10/627,232] was granted by the patent office on 2007-06-05 for method and apparatus for providing complex tissue stimulation patterns.
This patent grant is currently assigned to Advanced Neuromodulation Systems, Inc.. Invention is credited to George Van Campen, John Erickson.
United States Patent |
7,228,179 |
Campen , et al. |
June 5, 2007 |
Method and apparatus for providing complex tissue stimulation
patterns
Abstract
The invention relates to a stimulation device for creating
complex or multi-purpose tissue stimulation. Many typical
stimulation devices suffer from deficiencies in providing complex
stimulation patterns. Using a circuitry operable or programmable to
repeat and skip stimulation settings, a complex stimulation set may
be created. The repeating and skipping functionality may be
implemented in hardware or software. In this manner, complex
stimulations may be derived from simple circuitries. Furthermore,
these stimulations may be used to treat pain, stimulate bone
growth, and control motor disorders, among others.
Inventors: |
Campen; George Van (Ft.
Lauderdale, FL), Erickson; John (Plano, TX) |
Assignee: |
Advanced Neuromodulation Systems,
Inc. (Plano, TX)
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Family
ID: |
33163244 |
Appl.
No.: |
10/627,232 |
Filed: |
July 25, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040210271 A1 |
Oct 21, 2004 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60400366 |
Aug 1, 2002 |
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60398740 |
Jul 26, 2002 |
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60398704 |
Jul 26, 2002 |
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60398749 |
Jul 26, 2002 |
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Current U.S.
Class: |
607/46 |
Current CPC
Class: |
A61B
17/3468 (20130101); A61N 1/3708 (20130101); A61N
1/40 (20130101) |
Current International
Class: |
A61N
1/00 (20060101) |
Field of
Search: |
;607/46,48,47,67,69,70 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0811395 |
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Dec 1997 |
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EP |
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1 145 736 |
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Apr 2001 |
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EP |
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WO 87/07511 |
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Dec 1987 |
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WO |
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WO 01/93953 |
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Dec 2001 |
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WO |
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Primary Examiner: Manuel; George
Attorney, Agent or Firm: Lando; Peter R. Crawford;
Christopher S. L.
Parent Case Text
RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent
Application No. 60/398,749 entitled, "Method and Apparatus for
Providing Complex Tissue Stimulation Patterns" filed Jul. 26, 2002.
Additionally, this application incorporates by reference the prior
U.S. provisional application Nos. 60/398,704 entitled, "Method and
System for Energy Conservation in Implantable Stimulation Devices"
filed Jul. 26, 2002; 60/398,740 entitled, "High Frequency Pulse
Generator for an Implantable Neurostimulator" filed Jul. 26, 2002;
and 60/400,366 entitled, "Bendable Needle with Removable Stylet"
filed Aug. 1, 2002.
Claims
The invention claimed is:
1. A method for stimulating living tissue(s) with an electrical
neurostimulator, the method comprising: maintaining a plurality of
stimulation sets of stimulation parameters with each set of
stimulation parameters defining at least a pulse characteristic and
an electrode configuration in memory of the neurostimulator;
maintaining a repetition parameter for at least one of the
plurality of stimulation sets in memory of the neurostimulator,
wherein the repetition parameter identifies a number of times that
a pulse is to be repeated in a consecutive manner for the at least
one stimulation set; and stimulating living tissue(s) using a
substantially continuous set of pulses wherein the stimulating
includes (i) successively selecting a stimulation set from the
plurality of stimulation sets in a cyclical manner; (ii) generating
a pulse according to the pulse characteristic of the selected
stimulation set; and (iii) delivering the generated pulse to living
tissue(s) through electrodes according to the electrode
configuration of the selected stimulation set; wherein the
stimulating repeats the generating and delivering for the at least
one of the plurality of stimulation sets according to the
repetition parameter in a consecutive manner.
2. The method of claim 1 further comprising: maintaining a skipping
parameter for a second stimulation set of the plurality of
stimulation sets; wherein the stimulating omits performing the
generating and delivering for the second stimulation set for a
number of consecutive cycles within a predetermined number of
cycles according to the skipping parameter.
3. The method of claim 1 wherein the pulse characteristic is a
pulse amplitude.
4. The method of claim 1 wherein the pulse characteristic is a
pulse width.
5. An electrical neurostimulator for stimulating living tissue,
comprising: memory storing a plurality of stimulation sets of
stimulation parameters with each set of stimulation parameters
defining at least a pulse characteristic and an electrode
configuration; the memory further storing a repetition parameter
for at least one of the plurality of stimulation sets, wherein the
repetition parameter identifies a number of times that a pulse is
to be repeated in a consecutive manner for the at least one
stimulation set; a pulse generator that outputs a pulse having a
pulse characteristic; and a microprocessor operating under
executable instructions that: (i) successively selects a
stimulation set from the plurality of stimulation sets in a
cyclical manner; (ii) loads the pulse characteristic into a pulse
control associated with the pulse generator; (iii) configures an
output switch matrix according to the electrode configuration of
the selected stimulation set; (iv) causes the pulse generator to
output at least one pulse after the loading and configuring,
wherein the microprocessor causes the pulse generator to generate
adjacent pulses according to a frequency parameter; and (v) when
the selected stimulation set is the at least one stimulation set
associated with the repetition parameter, repeating (iv) according
to the repetition parameter within a stimulation cycle.
6. The electrical neurostimulator of claim 5 wherein the memory
further stores a skipping parameter for a second stimulation set of
the plurality of stimulation sets; and wherein the microprocessor
is further operable to omit selecting the second stimulation set
for a number of consecutive cycles within a predetermined number of
cycles according to the skipping parameter.
7. The electrical neurostimulator of claim 6 wherein the pulse
characteristic is a pulse width.
8. The electrical neurostimulator of claim 5 wherein the pulse
characteristic is a pulse amplitude.
9. A method for stimulating living tissue(s) with an electrical
neurostimulator, the method comprising: maintaining a plurality of
stimulation sets of stimulation parameters with each set of
stimulation parameters defining at least a pulse characteristic and
an electrode configuration in memory of the neurostimulator;
maintaining a repetition parameter for at least one of the
plurality of stimulation sets in memory of the neurostimulator,
wherein the repetition parameter identifies a number of times that
a pulse is to be repeated within a single cycle through the
plurality of stimulation sets; and stimulating living tissue(s)
using a substantially continuous set of pulses wherein the
stimulating includes (i) successively selecting a stimulation set
from the plurality of stimulation sets in a cyclical manner; (ii)
generating a pulse according to the pulse characteristic of the
selected stimulation set; and (iii) delivering the generated pulse
to living tissue(s) through electrodes according to the electrode
configuration of the selected stimulation set; wherein the
stimulating generates and delivers each adjacent pulse within a
single stimulation cycle through the plurality of stimulation sets
using a fixed interval; wherein the stimulating repeats the
generating and delivering for the at least one of the plurality of
stimulation sets to generate and deliver a number of pulses equal
to the repetition parameter within the single stimulation
cycle.
10. The method of claim 9 further comprising: maintaining a
skipping parameter for a second stimulation set of the plurality of
stimulation sets; wherein the stimulating omits performing the
generating and delivering for the second stimulation set for a
number of consecutive cycles within a predetermined number of
cycles according to the skipping parameter.
11. The method of claim 9 wherein the pulse characteristic is a
pulse amplitude.
12. The method of claim 9 wherein the pulse characteristic is a
pulse width.
Description
TECHNICAL FIELD OF THE INVENTION
This invention relates to a method and apparatus for tissue
stimulation. More specifically, this invention relates to a method
for creating complex stimulation patterns with a stimulation device
coupled to one or more leads with one or more electrodes.
BACKGROUND OF THE INVENTION
Electronic stimulation systems may be used to control pain or motor
disorders. Such systems have also been used to stimulate bone
growth.
For example, application of an electrical field to spinal nervous
tissue can effectively mask certain types of pain transmitted from
regions of the body associated with the stimulated tissue. More
specifically, applying particularized electrical pulses to the
spinal cord associated with regions of the body afflicted with
chronic pain can induce paresthesia, or a subjective sensation of
numbness or tingling, in the afflicted bodily regions. This
paresthesia can effectively inhibit the transmission of non-acute
pain sensations to the brain.
Electrical energy, similar to that used to inhibit pain perception,
may also be used to manage the symptoms of various motor disorders,
for example, tremor, dystonia, spacticity, and the like. Motor
spinal nervous tissue, or nervous tissue from ventral nerve roots,
transmits muscle/motor control signals. Sensory spinal nervous
tissue, or nervous tissue from dorsal nerve roots, transmit pain
signals.
Electrical energy may be commonly delivered through electrodes
positioned external to the dural layer surrounding a spinal cord.
The electrodes are carried by two primary vehicles: the
percutaneous lead and the laminotomy lead.
Percutaneous leads commonly have two or more electrodes and are
positioned within an epidural space through the use of an
insertion, or Touhy-like, needle. An example of an eight-electrode
percutaneous lead is an OCTRODE.RTM. lead manufactured by Advanced
Neuromodulation Systems, Inc. of Allen, Tex.
Operationally, an insertion needle is passed through the skin,
between the desired vertebrae, and into an epidural space which is
defined by a dural layer in combination with the surrounding
vertebrae. The stimulation lead is then fed through the bore of the
insertion needle and into the epidural space. Conventionally, the
needle is inserted at an inferior vertebral position, for example,
between vertebrae L1 and L2 (Li/L2), and the stimulation lead is
advanced in a superior direction until the electrodes of the
stimulation lead are positioned at a desired location within the
epidural space, for example, at T10. In a lateral position,
percutaneous leads are typically positioned about a physiological
midline.
As an example of application, the above methodology is commonly
used for the management of sympathetically maintained pain (SMP).
It is generally believed that due to the sympathetic nature of SMP,
stimulation leads positioned about a physiological midline provide
sufficient electrical energy to interrupt the transmission of SMP
signals. However, the above-described conventional technique may be
used for the management of sympathetically independent pain (SIP),
stimulating bone growth, and treating muscle disorders, among
others.
As an alternative to spinal cord stimulation, electrical energy may
be delivered to selected peripheral nerves using a peripheral nerve
stimulation system. Peripheral nerve stimulation involves
administration of electrical energy to a localized group of
peripheral nerves through placement of one or more leads at the
peripheral nerve site. Unfortunately, if a patient's pain is
widespread, a patient may require a plurality of stimulation leads
to be implanted. The surgical procedure necessary for stimulation
lead implantation is significant and can be quite painful.
Additionally, because peripheral stimulation leads are implanted in
"active" areas of the body (e.g., arms and legs), the leads
typically lack long-term placement stability. Lead movement, or
lead migration, can affect the quality of pain relief. Further,
significant lead movement that undermines the intended stimulation
effect may require additional corrective surgeries to reposition
the stimulation leads.
In each of these cases, the stimulation device may be coupled to
one or more leads with one or more electrodes. Depending on the
application and the purpose of the stimulation, varying stimulation
patterns and electrical fields may be desired. An applied
electrical field is defined by the polarity of each electrode of
the stimulation lead. Conventionally, each electrode is set as an
anode (+), cathode (-), or neutral (off). For a four electrode
percutaneous lead there exists approximately 50 electrode
combinations. For an eight electrode percutaneous lead, the number
of possible electrode combinations grows to approximately 6050.
Further, various combinations of pulses and pulse frequencies may
be used with varying sets of electrodes.
Many typical stimulation devices are limited in their ability to
deliver stimulations in complex patterns. Further, these typical
stimulation devices may not be used in multi-purposes
stimulation.
As such, many typical stimulation devices suffer from deficiencies
in providing complex multi-purpose stimulation patterns. Many other
problems and disadvantages of the prior art will become apparent to
one skilled in the art after comparing such prior art with the
present invention as described herein.
SUMMARY OF THE INVENTION
Aspects of the present invention may be found in a stimulation
device for providing complex and/or multi-purpose stimulations to
various tissues. The stimulation device may include a pulse
generator, a switching circuitry, one or more means for pulse
repetition, one or more means for pulse skipping, and one or more
leads with one or more electrodes. The means for pulse repetition
may include a counter and parameter. In addition, the means for
pulse skipping may include a counter and parameter. Each repetition
means and/or skipping means may be associated with a stimulation
setting. Further, these means may be implemented in hardware,
software, or a combination of hardware and software.
Further aspects of the invention may be found in a method for
stimulating tissue with complex and/or multi-purpose stimulation
pulse patterns. A switching circuitry associated with the
stimulation device may be configured to couple a particular
electrode set. The set may be stimulated with a pulse from a pulse
generator according to a stimulation setting. The pulse may be
repeated in accordance with a repetition parameter. The switching
circuitry or pulse characteristics may then be reconfigured in
accordance with a subsequent stimulation setting. A pulse may then
be generated in accordance with the subsequent stimulation setting.
The subsequent setting may then be repeated and the settings
reconfigured through an array of settings. Once the array of
settings has been stimulated, the pattern may begin again. Or, in
accordance with the skipping means, various settings may be skipped
for subsequent stimulations of the array.
As such, an apparatus and method for complex and/or multi-purpose
stimulation of tissue is described. Other aspects, advantages and
novel features of the present invention will become apparent from
the detailed description of the invention when considered in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
For a more complete understanding of the present invention and
advantages thereof, reference is now made to the following
description taken in conjunction with the accompanying drawings in
which like reference numbers indicate like features and
wherein:
FIG. 1 is a schematic diagram depicting a stimulation device;
FIG. 2 is a pictorial depicting an exemplary embodiment of a
implanted stimulation device;
FIG. 3 is a schematic block diagram depicting an exemplary
embodiment of a stimulation device;
FIG. 4 is a schematic block diagram depicting an exemplary
embodiment of a controller for use in the stimulation device of
FIG. 3;
FIG. 5 is a schematic block diagram depicting an exemplary
embodiment of the system as seen in FIG. 3;
FIG. 6A is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 6B is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 6C is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 7A is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 7B is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 7C is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 8A is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 8B is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 8C is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG.
3;
FIG. 8D is a graph depicting an exemplary embodiment of a
stimulation setting for use in the stimulation device of FIG. 3;
and
FIG. 9 is a block flow diagram depicting an exemplary method for
use by the system as seen in FIG. 1.
Corresponding reference numerals indicate corresponding parts
throughout the several views of the drawings.
DETAILED DESCRIPTION OF DRAWINGS
Several conditions may benefit from electrical pulse stimulation or
modulation of tissue. These conditions include pain, bone growth,
cardiac arrest and arrhythmias, peripheral vascular disease (PVD),
angina pectoris, and various motor disorders. The electrical pulse
stimulation can be delivered by a lead with several electrodes
placed near the tissue to be stimulated. In this configuration, the
lead is connected to a stimulation device, which is either
implanted corporally or external to the body.
FIG. 1 is an exemplary implanted stimulation system 10. Device 12
may be implanted in a patient. Attached to device 12 is lead 14,
which terminates in a set or array of electrodes 16. Device 12 may
be used to treat various conditions such as arrhythmias, muscle
tremors, tissue damage, and chronic pain, among others.
Device 12 may take various forms. These forms may include implanted
pulse generators, neurostimulators, muscle stimulators, and
defibrillators, among others.
Lead 14 and electrodes 16 may take various forms. These forms may
include cylindrical leads and electrodes, paddles, and lamitrodes,
among others. Lead 14 may have one or more electrodes 16 and these
electrodes 16 may be shaped in accordance with various functions.
Furthermore, more than one lead 14 may be attached to device
12.
Stimulation device 12 may be configured to stimulate one or more
sets of electrodes with one or more pulses having various pulse
characteristics. Together, the sets of electrodes and pulse
characteristics make stimulation settings. For each stimulation
setting, each electrode is set as an anode (+), cathode (-), or
neutral (off). For a four electrode percutaneous lead there exists
approximately 50 electrode combinations. For an eight electrode
percutaneous lead, the number of possible electrode combinations
grows to approximately 6050. These electrode settings are combined
with pulse characteristics and pulse patterns to stimulate the
tissue.
For example the device may act to stimulate the heart muscle, bone,
spinal nervous tissue, other muscle tissue, and other nervous
tissue, among others. FIG. 2 depicts an exemplary embodiment of a
neurostimulator implanted in the torso 30 of an individual. In this
exemplary embodiment, device 32 is installed such that lead 34
extends into the spinal foramen 36 as defined by the vertebrae 38.
Lead 34 terminates with one or more electrodes. These electrodes
are used to stimulate or modulate nervous tissue. The stimulation
or modulation may function to prevent muscle tremor and/or mask
pain. The function and location of effect may be affected by the
location and stimulation characteristics of the electric field
pulses delivered by device 32.
The stimulation activity and tissue type may be best suited to
differing pulse patterns. For example, stimulation of bone growth
may use periodic bursts of high frequency pulses. On the other
hand, pain masking may require consistent pulsing at a lower
frequency. Alternately, pain masking may be produced by patterns of
varying pulse frequency and amplitude.
FIG. 3 is an exemplary embodiment of a stimulation device for
creating complex and/or multi-purpose stimulation sets. The device
50 may have a receiver 52, transmitter 58, power storage 54,
controller 55, switching circuitry 56, memory 57, pulse generators
60 and 62, and processor 63. Device 50 is typically coupled to one
or more leads 64 and 66. Leads 64 and 66 terminate in one or more
electrodes 65 and 67. However, some, all, or none of the components
may be included in device 50. Further, these components may be
together, separate, or in various combinations, among others.
Receiver 52 may take various forms. These forms may include a
circuitry, antenna, or coil, among others. The receiver 52 may or
may not function to receive instructions and data. Further, the
receiver 52 may or may not function to receive power that may be
used by the device and/or stored in the power storage 54.
Similarly, the transmitter 58 may take various forms including a
circuitry, antenna, or coil, among others. The transmitter 58 may
function to transmit data and/or instructions. However, the
receiver 52 and transmitter 58 may or may not be included or may be
together, separate, combine various components, among others.
The power storage 54 may take various forms. These forms may
include various batteries.
Controller 55 may take various forms. These forms may include those
discussed in FIG. 4 or other means for modulating and controlling
pulses and signals. Further, aspects of controller 55 may be
implemented as software, hardware, or a combination of software and
hardware.
Switching circuitry 56 may take various forms. These forms may
include various contacts, relays, and switch matrices, among
others. Further, switching circuitry 56 may or may not include one
or more blocking capacitors associated with connections to the
leads. These blocking capacitors may block direct connection to the
leads and/or function to build charge that may be discharged
between signal pulses. Furthermore, switching circuitry 56 in
combination with microprocessor 63 and/or controller 55 may
function to drop, skip, or repeat stimulation patterns.
Memory 57 may take various forms. These forms may include various
forms of random access memory, read-only memory, and flash memory,
among others. The memory may be accessible by controller 55, the
switching circuitry, and/or processor 63. Further, the memory may
store various stimulation settings, repetition parameters, skipping
parameters, programs, instruction sets, and other parameters, among
others.
Processor 63 may take various forms. These forms may include logic
circuitry or microprocessors, among others. Processor 63 may
function to monitor, deliver, and control delivery of the
modulation or stimulation signal. Further, processor 63 may
manipulate switching circuitry 56. This manipulation may or may not
be in conjunction with controller 55.
The one or more pulse generators 60 and 62 may take various forms.
These forms may include a clock driven circuitry, or an oscillating
circuitry, among others. The pulse generator(s) 60 and 62 may
deliver a electric or electromagnetic signal through switching
circuitry 56 to leads 64 and 66 and electrodes 65 and 67. The
signal may be modulated by circuitry associated with the switching
circuitry 56, controller 55, and/or processor 63 to manipulate
characteristics of the signal including amplitude, frequency,
polarity, and pulse width, among others.
In one exemplary embodiment, microprocessor 63 may interact with
switching circuitry 56 to establish electrode configurations. The
pulse generator may then generate a pulse and, in combination with
microprocessor 63 and switching circuitry 56, stimulate the tissue
with a pulse having desired characteristics. The controller 55 may
interact with microprocessor 63 and switching circuitry 56 to
direct the repetition of the pulse. Alternately, switching
circuitry 56 may be reconfigured to subsequent stimulation settings
in an array of stimulation settings. The controller 55 may then
direct the skipping or with settings in the array of settings for
one or more passes through the stimulation setting array.
Controller 55 may be implemented as software for use by
microprocessor 63 or in hardware for interaction with
microprocessor 63 and switching circuitry 56, among others.
FIG. 4 is a schematic block diagram depicting an exemplary
embodiment of a controller. The controller 110 may have one or more
repeat parameters 112, one or more skip parameters 114, other
parameters 116, counters 118, and interfaces 120.
The one or more repeat parameters 112 may be associated with one or
more of the stimulation settings. For example, a stimulation device
may have eight stimulation settings. Each of the eight stimulation
settings may have a repeat parameter 112 associated with it.
Alternately, a repeat parameter 112 may be associated with a given
stimulation setting such as a first stimulation setting. The repeat
parameter 112 may cause a given stimulation setting to repeat a
number of times in accordance with the repeat parameter 112.
Similarly, skip parameters 114 may be associated with one or more
of the stimulation settings. Each of the eight stimulation settings
may have a skip parameter 114 associated with it. Alternately, a
skip parameter 114 may be associated with a given stimulation
setting such as a first stimulation setting. Skip parameter 114 may
cause a given stimulation setting to be dropped or skipped for a
given number of cycles through the array of stimulation settings in
accordance with skip parameter 114. Various other parameters 116
may also be associated with controller 110.
In addition, various counters 118 may be associated with controller
110. These counters 118 may be used in determining which pulses or
stimulation sets to skip or when to stop repeating a stimulation
set.
Further, controller 110 may have various interfaces 120. These
interfaces enable communication with the switching circuitry,
microprocessor, and pulse generator, among others. These interfaces
may take the form of circuitry in the case of a hardware based
controller. Alternately, these interfaces may take the form of
software interfaces in the case of a software based controller. In
addition, various combinations may be envisaged.
FIG. 5 is a schematic block diagram depicting an exemplary
embodiment of the system. This exemplary embodiment 70 may have a
microprocessor 74, interface 72, program memory 76, clock 78,
magnet control 80, power module 84, voltage multiplier 86, pulse
amplitude and width control 88, CPU memory 82, and multi-channel
switch matrix 90. However, these components may or may not be
included and may be together, separate, or in various
combinations.
Microprocessor 74 may take the form of various processors and logic
circuitry and can function to control pulse stimulations in
accordance with settings 1 through N stored in the CPU memory 82.
Further, microprocessor 74 may function in accordance with programs
stored in program memory 76.
Program memory 76 may take various forms. These forms may include
RAM, ROM, flash memory, and other storage mediums among others.
Further, program memory 76 may be programmed using interfaces
72.
These interfaces 72 may be accessed prior to implanting to program
microprocessor 74, program memory 76, and or CPU memory 82. These
forms may include ports or connections to handheld circuitry,
computers, keyboards, displays, and program storage, among others.
Alternately, interfaces 72 may include means for interaction and
programming after implanting.
Clock 78 may be coupled to microprocessor 74. Clock 78 may provide
a signal by which microprocessor 74 operates and/or uses in
creating stimulation pulses.
Magnet control 80 may also interface with microprocessor 74 and
functions to start or stop stimulation pulses. Alternately, a
receiver or other means may be used to accomplish the same task.
The receiver may or may not function to provide programming
instruction, power charge, and on/off signals.
System 70 may also have a power supply or battery 84. This power
supply 80 may function to power the various circuitries such as
clock 78, microprocessor 74, program memory 76, and CPU memory 82,
among others. Further, power supply 80 may be used in generating
the stimulation pulses. As such, the power supply may be coupled to
the microprocessor 74, a voltage multiplier, and/or a switch matrix
90.
CPU memory 82 can take various forms, which may include RAM, ROM,
flash memory, and other storage mediums among others. CPU memory 82
may store stimulation settings 1 through N. These stimulation
settings may include electrode configuration, pulse frequency,
pulse width, pulse amplitude, and other limits and control
parameters. The repetition and skipping parameters can be stored in
CPU memory 82 and may be associated with each of the stimulation
settings 1 through N. Microprocessor 74 may uses these stimulation
settings and parameters in configuring switch matrix 90,
manipulating pulse amplitude and pulse width control 88, and
producing stimulation pulses.
Switch matrix 90 may permit more than one lead with more than one
electrode to be connected to system 70. Switch matrix 90 may
function with other components to selectively stimulate varying
sets of electrodes with various pulse characteristics.
In this exemplary embodiment, the controller may be implemented in
software for interpretation by microprocessor 74. Alternately, a
hardware implementation may be coupled to microprocessor 74, pulse
amplitude controller 88, and switch matrix 90. However, various
embodiment of the controller, system 70, and implementation may be
envisaged.
The repetition means as seen in relation to the controller of FIG.
4 or microprocessor 74 of FIG. 5 enables a stimulation set to be
repeated before switching to a different stimulation set or pulse
characteristic. FIG. 6A is a graph depicting an exemplary
embodiment of stimulation sets. In this embodiment, the first
stimulation set may be repeated N number of times before the
stimulation settings are changed to the next set. Subsequently, a
pulse is directed in accordance with a second stimulation set after
which the pattern is repeated.
In another exemplary embodiment, the first stimulation set is
pulsed, followed by a repetition of the second set for N number of
pulses as seen in FIG. 6B. In another embodiment, both sets may be
pulsed for N number of pulses as seen in FIG. 6C. The sets may be
pulsed differing number of times. In addition, more than two
stimulation sets may be used.
FIG. 7A is a graph depicts another exemplary embodiment of an array
of stimulation sets. In this case, the first stimulation set is
repeated. This repetition may be achieved through a repetition
means associated with the first set. Alternately, the apparent
repetition may be achieved by dropping or skipping the second and
third stimulation sets N number of cycles through the stimulation
array.
FIG. 7B shows the effect of skipping the first stimulation set N
number of cycles through the stimulation array. The first
stimulation set is pulsed, followed by the second then third
stimulation sets. However, on the next cycle, the first stimulation
set is skipped. The first stimulation set may be skipped N number
of cycles in accordance with the skipping means or parameters.
In another exemplary embodiment seen in FIG. 7C, the skipping and
repetition means and methods may be combined to form a more complex
pattern. In this case, the first stimulation setting receives a
repeated pulse. Subsequently, the array cycles through the second
then third stimulation settings. However, the first pulse is
skipped for the next N cycles. The pattern is then repeated with a
repeated first pulse, followed by a cycling, followed by the
skipping of the first stimulation set.
The skipping and repeating means and methods may also be used to
augment the stimulation of a single electrode set with varying
pulse characteristics. FIG. 8A depicts a pulse pattern placed on a
single electrode set. The pulse pattern repeats a first pulse
characteristic. In this example, the amplitude is shown to vary.
Subsequently, the amplitude is changed for a second stimulation
that may be repeated. Further stimulation sets may have various
characteristics through the cycle of the array. In the example seen
in FIG. 8A, the four sets may be seen as step changes in amplitude
before the cycle is repeated.
In another exemplary embodiment, pulses may be skipped to
effectively change the frequency of the pulse. FIG. 8B shows a
single set of electrodes receiving a stimulation in which a first
pulse characteristic is repeated, then skipped. In this case, the
apparent frequency change may be implemented as two stimulation
sets, one being repeated then skipped. Alternately, the pattern may
be achieved through other combinations of repetition and
skipping.
FIG. 8C shows a combination of changing frequency and amplitude on
a single set of electrodes. This example may also be implemented as
two stimulation sets utilizing the repetition and skipping
features.
In another exemplary embodiment, FIG. 8D depicts the use of
stimulation sets which differ in pulse width characteristics.
However, various combinations of stimulation settings may be used
in conjunction with the repetition means and the skipping means.
These combinations may be customized to specific applications.
An exemplary method for use by the system is seen in FIG. 9. The
method 130 may or may not include a step of reconfiguring the
system for the next stimulation set as seen in block 132. In a
system with multiple stimulation sets, the system may select the
next stimulation set in an array. Alternately, the system may only
apply the method to one stimulation set in the array.
The system then determines the presence or value of a skip counter
and act accordingly as seen in block 134. In the case of a
decrementing counter, the test may be to determine if the counter
is non-zero. However, an incrementing counter may be used for
which, the test would be to determine if the counter value is equal
to a skip parameter is achieved. On the other hand, in cases where
a stimulation set is not present for a specific stimulation set,
the system may skip to another step.
If the skip counter is not zero in the case of a decrementing
counter or has not reached the value of the skip parameter in the
case of an incrementing counter, the system may decrement or
increment the counter, respectively, as seen in block 136.
Effectively, the pulse or stimulation is skipped or dropped. Then,
the next stimulation set may be selected as seen in block 132.
If the skip counter has reached the appropriate value, the counter
may be reset as seen in block 137. For a decrementing counter, the
counter may be reset to the skip parameter value. For an
incrementing counter, the counter may be reset to zero.
The system then tests for a repeat counter and its value as seen in
block 138. In the case of a decrementing counter, the system tests
to determine if the counter is zero. Alternately, in the case of an
incrementing counter, the system tests to determine if the counter
has reached the repeat parameter value.
If the counter has not reached to appropriate value, the system
stimulates the tissue in accordance with the stimulation set as
seen in block 140. The counter is then decremented if it is a
decrementing counter or incremented if it is an incrementing
counter as seen in block 142. The system then tests the value of
the counter again as seen in block 138.
However, if the counter has reached the desired value, the system
resets the counter as seen in block 139. If the counter is a
decrementing counter, the counter may be reset to the repeat
parameter value. However, if the counter is an incrementing
counter, the counter may be reset to zero. Subsequently, the system
may select the next stimulation set as seen in block 132.
However, these steps may or may not be included in the method.
Further, the steps may be arranged in various sequences.
As such, a stimulation device for creating complex and/or
multi-purpose tissue stimulation is described. In view of the above
detailed description of the present invention and associated
drawings, other modifications and variations will now become
apparent to those skilled in the art. It should also be apparent
that such other modifications and variations may be effected
without departing from the spirit and scope of the present
invention as set forth in the claims which follow.
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